Ventilation system



Jan. 3, 1928.

R. V. LONG VENTILATION SYSTEM Filed April 29, 1925 2 Sheets-Sheet 1 Jim3, 1928f 1,654,981

. R.. V. LONG VENTILATION SYSTEM Filed April 29. 1925 2 Sheets-Sheet 2Patented Jan. 3, 1928.

UNITED STATES PATENT OFFICE.

RAYMOND V. LONG, 0F RICHMOND, VIRGINIA. ASSIGNOB T0 RICHMOND EQUIPMENTSUPPLIES, INCORPORATED, OF RICHMOND, VIRGINIA.

VENTILATION SYSTEM.

Application filed April 29, 1925. Serial No. 26,715.

- This invention relates to ventilation systems and more particularly toa ventilation system for halls, schools, and the like, adapted tocontrol the amount of air passing therethru in a uniform and eflicientmanner.

The ventilation of buildings, as for instance for school use, requires adefinite volume of air. per minute for each person in a room, therequired volume being obtained by providing a predetermined number ofair changes per hour for each room' of the building. Ventilation systemsof the blower type have been designed to effect the necessary airchanges, but this type of system involves an extensive installation andcumbersome ducts, together with extensive upkeep costs. In the forcedair system, an undue waste of heated air thru the vent ducts occurs,resulting in an over-cooling etlect. The use of a straight steaminstallation, which is of the most common type, depending upon openwindow ventilation, is accompanied by many difficulties, mainly, that ofa temperature difference exceeding ten degrees, particularly when a windis blowing directly against the windows from which the fresh air istaken, so that if any fresh air is permitted to the room at all, a toogreat cooling eifect, due to the overabundance of air passing thru theroom,

results.

Therefore, one of the objects of my invention is to provide an efiicientventilation system which automatically furnishes the necessary number ofair changes while preventing an over-abundance of air passing thru theroom to be ventilated.

A further object of my invention is to provide a reliable ventilationsystem of the type particularly adapted for schools, in connection witha steam installation where the ventilation is dependent upon the openingof the windows, which system limits the amount of heated air passing outof the room to the proper scientific volume required by each personoccupying the room.

A further object is to provide in a simple and practical ventilationsystem a vent check which, depending on the velocity of the heated airleaving aroom, automatically provides the required number of air changesper hour without permitting an over-abundance of air passing thru theroom.

it further object is to provide in a ventilation system a vent check ofthe above described character which automatically limits the amount ofair passing from a room depending on the velocity thereof, thereby toprevent an over-abundance of air passing thru the room.

A further object is to provide a device of the character described whichis durable in construction, economical in manufacture and installation,efficient in operation, and which accomplishes among others the objectsset forth.

The invention accordingly consists in the features of construction, thecombination of parts, and in the unique relationv of the various membersand the relative proportioning and dispositioning thereof, all as moreclearly outlined herein.

To enable others skilled in the art to fully comprehend the underlyingfeatures thereof, in order that they may embody the same, by numerousmodifications in structure, and relation contemplated by this invention,drawings depicting preferred form of the invention have been annexed aspart of this disclosure, and in such drawings like characters ofreference indicate corresponding parts throughout all the views, ofwhich- Figure 1 a view of a chamber, in perspective of a classroom type,having installed therein the proposed form of ventilation system.

Figure 2 is a view in perspective of the vent check.

Figure 3 is a sectional view taken on the line 33 ofv Fig. 2.

Figure t is an end view of the type of blade used in the vent check.

Figures 5 and 6 are details of the blade stop devices.

Figure is a detail of the bearing plate.

Referring now to the drawings and more particularly to Figure 1, thenumeral character 10 designates a chamber such as a classroom, which isheated by a straight steam installation, the radiators 11 thereof beingpositioned below the windows 12. Air, entering the room over deflectors13 arranged at the base of the windows, rises towards the ceiling due tothe steam radiators being positioned below the deflectors. The freshlyheated air is distributed about the room and passes therefrom underwardrobe doors 14 and thence thru a vent check 15 which is hung from anopening in the ceiling of a wardrobe 16, and finally thru a duct 17 to aventilator (not shown) on the roof of the building.

The vent check 15 (see Figures 2 and 3) comprises a casing 20,substantially rectangular in form, and made preferably of galvanizediron with all joints riveted. Flanges 21 are provided at the top of thecasing for hanging the casing to the ceiling of the wardrobe 16 by anysuitable means projecting thru holes 22.

A plurality of blades 24, of substantially Sshaped form (see Figure 4e)are mounted within the casing 20 by means of axles 25 projecting thrucenter bushings 27 of theblades. The blades are made as light aspossible, preferably of aluminum of a gage varying with the size of thevent check device. The rods or axles 25, preferably of bronze, rest inbearings 28, positioned on the side walls of the casing 20, which arealso preferably of bronze, and are fixedly joined to the casing 20 as byany suit-able means such as rivets 30. Cut in the bearing plates 28, arearcuate slots 31 (see Figure 7 having a radius of approximately one anda half inches, in which the ends of the bronze rods 25 rest. These slotspermit of a rolling bearing feature, as the rods 25 simply roll in thebearings 28 as the blades 24: turn thru an arc of 90, thus practicallyeliminating friction between these parts. In their normal'open position,the blades extend in the direction of flow of air from the room topermit a substantially free and unrestricted passage of the air thru thecasing.

Referring to Figure 2, a plurality of small holes 32 are provided inblades 24, across a half portion thereof. These holes permit of thebalancing of the blades whereby they may be rotated about their centerpoint upon a certain air velocity of the air passing thru the casing 20being reached. Split shank bolts 35 are also provided, passing thru theblades 24, and carry the nut or weight 36, as a means for furtherbalancing the blades to turn at the proper air velocity. The bolts,after the blade has been properly balanced, are bent back into thedotted line position (see Figure 4), to prevent the nut or weight 36from loosening and dropping oif. The velocities of air to which theblades are re sponsive are determined by the number of air changes founddesirable so that the degree ofbalance of the blades bears a directrelation to the number of air changes found to bev best suited toparticular needs.

The lower portion or inlet 37 to the casing is angularly disposed withrespect to the upper portion thereof, as shown in Figure 3,

to permit of some passage of air thru the ducts even when the blades areclosed.

Mounted on the side walls of the casing '20 adjacent the bearing plates28,are stop members 40 (see Figures 5 and 6)' having their projectingarms 41 covered with shock reducing material such as piano felt, whichis glued on and riveted to the arms 41. The felts are; chemicallytreated or impregnated to prevent disintegration by moths, insects, andthe like. It will thus be obvious that, due to the position of thestops, the blades cannot revolve thru a greater are than that of 9\necessary to open and close the vent check. The underside of the ventcheek mi ght advantageously be'covered with a perforate protectingcovering such as a wire mesh to prevent anything from hitting the bladesfrom below.

The operations of the system is briefly as follows: Air enters the room10 at the base of the windows 12.. and is deflected upwardly by means ofthe deflectors 13 and the positioning of the radiators 11 below thewindows, from whence it is distributed about the room. is shown byarrows inFigure 1. air leaves the room beneath the wardrobe doors 14.passes thru the vent check 15 and duct 17 from whence it is dischargedinto the'atmosphere. In its passage thru the room, the air attains avelocity dependent upon the amount of air entering the rcom and alsoupon the rate at which it is permitted to flow therefrom. It has beenfound that to provide each person in the room with sufficient volume ofair per hour, it is necessary that a prescribed number of complete airchanges per hour. usually it to 6'. take place within the room. It'willbe seen. from the above that by balancing the blades of the vent el'ieckto permit of the passage of air at a certain velocity from the room thruthe vent duct 17 and to substantially close the vent upon a greateroutflow velocity of the air being reached, the number of air changespermitted the room in an hour which is dependent upon the velocity offlow of air from the room may automatically be regulated. Thus, bydetermining the outflow velocity of air necessary to effect the desirednumber of air changes, per hour,'a.ul balancing the blades 24 to closethe duct atany increased velocity, the vent duct will permit the air topass'therethru to allow freshly heated air to enter the room, but

will automatically prevent any over-abundance of fresh air, due to theblades closing the discharge of air from the room upon a greatervelocity of flow than that as determined necessary, being reached.

Further, the number of air changes permitted'the room, may be varied byvarying the degree of balance of the blades 24 to close the vent ductwithin a. given range of outflow velocities so that the vent check isoperative within reasonable limits to effect various desired airvelocities and air changes.

As hereinbefore stated, it is desirable to provide a space about theblades to permit some air to pass thru the device even when the bladesare in closed position in order that all ventilation is not cut oil.This space is preferably such that approximately one complete air changeper hour would takeplace if the blades were kept continuously closedwhich is sufficient to furnish a degree of ventilation when the weatherconditions are abnormal.

The ventilation system as comprehended with the scope of the abovedescribed invention thus provides a simple and practical means ofproviding the required volume of freshly heated air per person within aroom and limits the amount of heated air passing from the room by meansof the automatioally operating vent check so that an over abundance offresh air passing thru the room is prevented. As hereinbefore pointedout, the system is particularly adapted for use with a straight steaminstallation where ventilation is dependent upon opening of the windows,but I do not wish to be limited in this respect, as it is obvious thatthe vent check is equally applicable and advantageous to other types ofinstallations.

In view of the above, it will be seen that the several objects of theinvention are achieved and other advantageous results attained. As manychanges could be made in carrying out the above construction, withoutdeparting from the scope or the invention, it is intended that allmatter contained in the above description or shown in the accompanyingdrawings shall be interpreted as illustrative and not in a limitingsense.

I claim:

1. A system of ventilation comprising means for admitting air into aroom, and means for permitting air to flow from the room, said lastmentioned means comprising a vent duct, a plurality of pivotally mountedblades positioned in the vent duct, said blades normally permitting flowof air from the room thru the vent duct, and operative to substantiallyclose said vent duct when the flow of air thru the vent exceeds apredetermined velocity, means to cause the air to flow to said blades atan oblique angle with respect to a plane thru the axes of the blade, andmeans permitting the return of said blades to normal open position whenthe abnormal outflow velocity is relieved.

2. A vent check adapted to be positioned in the air discharge duct of aroom to provide a predetermined number of air changes in the room,comprising, in combination, a casing, and a plurality of balanced bladespivotally mounted in said casing to normally permit a substantiallyunrestricted passage of air thru the casing, said blades beingresponsive to the velocity of air flow thru the duct from the room andmeans to so direct air against said blades as to cause them tosimultaneously swing in the same direction.

3. A vent check adapted to be positioned in the air discharge duct of aroom, com prising, in combination, a casing, and a plurality of bladespivotally mounted in said casing provided with holes therethrough toassist in the balancing thereof, said blades being balanced and adaptedto maintain a relatively vertical position upon normal velocity of airoutflow thru the casing, said casing being provided with means to causethe air to travel toward the blades at an oblique angle with respect toa plane through the axes of the blades, and to rotate about their pivotpoints to a relatively horizontal position to substantially close thevent duct upon an increase of velocity of air outflow, and stop memberson said casing adapted to abut against said blades in their vertical andhorizontal positions, thereby to limit the rotation of the blades.

4. A vent check adapted to be positioned in the air discharge duct of aroom, comprising, in combination, a casing, a plurality of substantiallyS-shaped blades, axles mounted! substantially centrally in said blades,bearing plates on said casing having arcuate slots therein, said axlesprojecting into said arcuate slots whereby a rolling bearing for saidblades is provided, said blades being balanced and responsive to thevelocity of air flowing thru said duct.

5. A vent check adapted to be positioned in the air discharge duct of aroom, comprising. in combination, a casing, a plurality of bladespivotally mounted in said casing, means to provide a rolling bearingsurface for said blades with respect to said casing, means on saidcasing to limit the rotation of said blades from a substantiallyvertical to a substantially horizontal position, means on said casing todirect the flow of air from the room at an oblique an le with respect toa plane through the axes of said blades, said blades being balanced torespond to the outflow velocity of air from the room, and therebyoperative to check the flow of air from the room when the rate ofoutflow exceeds a predetermined velocity and to open the vent duct tothe air outflow when the blades are relieved of excess outflow velocity.

6. A vent cheek adapted to be positioned 5 in the air passage duct of aroom comprising, vin combination, a casing and a plurality of balancedblades pivotall; mounted in said casing, said blades being responsive tothe velocity of air flow from the room,

and said casing being provided Witha plurality of angularly disposedbafiies in parallel relation to direct the air against the blades at anoblique angle with respect to a plane thru the axes of said blades.

Signed at Richmond, Virginia, this 16th day of April, 1925.

RAYMOND V. LONG.

